1. Field of the Invention
The present disclosure relates to a method and an apparatus for growing a silicon single crystal from a melt. More specifically, it relates to a method for growing a silicon single crystal according to the Czochralski method while imposing a horizontal magnetic field on the melt, the so-called HMCZ method.
2. Background Art
It is known, e.g. from EP 0 745 706 A1, that imposing a horizontal magnetic field on the melt reduces melt convection and the dissolution of SiO from the crucible. As a consequence, imposing a horizontal magnetic field on the melt is a suitable strategy for producing silicon single crystals having a relatively low oxygen concentration.
It is further known that the oxygen concentration in a silicon single crystal can be lowered by increasing the flow rate of inert gas flowing between the silicon single crystal and a heat shield to a melt free surface. The increased gas flow rate enhances the transport of SiO evaporating from the melt so that less oxygen is incorporated in the growing silicon single crystal.
JP2004-196569 A discloses an HMCZ method comprising simultaneously controlling the axial position of the horizontal magnetic field and the intensity of the gas flow in order to produce low-oxygen silicon single crystals. However, controlling the axial position of the horizontal magnetic field requires a complex control system.